4x is CLV, so I don't expect to see a ring. At higher speed, yeah, you may see the speed change.
How about burning a disc at 16x? At CAV, I don't think you'll see a ring.
Yeah, I'm joking. But seriously, if your 3520 does something that others don't, then it's probably faulty, and using 4x media isn't something close to a "solution". I'd rather throw it away immediately or replace it if warranty is remaining.
On the other hand, if what you observe is what everyone else observe, and everyone else think there's no problem.. why do you worry?
What of the above 2 cases do you think you belong to? (I don't know much of 3520, so I don't have the answer.)